Chicken farmers in the northeastern United States are dealing with a form of bird flu different from the virus in Asia. Officials say it is the form H7. The H7 virus does not have a history of infecting people. But it does kill chickens, and it spreads easily.

The virus was first discovered on a farm in Delaware that provided live chickens to a market in New York City. States officials ordered that farm and another one to destroy thousands of chickens. Officials also banned the sales of live chickens. After Delaware, cases were reported in New Jersey and Pennsylvania.

The United States is the biggest producer and exporter of chicken. The American share of the export market in two-thousand-one was valued at nearly two-thousand-million dollars. That year, eighteen-percent of all American chicken production was exported.

Because of the H7 outbreak, a number of nations have barred imports of American chicken. Some including Russia barred imports only from the affected areas. Russia is the biggest importer of American chicken products.

Others ordered bans on chicken from anywhere in the United States. These countries included China, Japan, Malaysia, Singapore and South Korea. The United States Agriculture Department says it does not believe the import bans will last long.

In Asia, officials have been working to control the spread of the avian influenza virus known as H5N1. That virus has killed millions of chickens in several countries. The number of human deaths reached twenty last week in Vietnam and Thailand.

The bird flu outbreak in Asia has caused economic damage. The United Nations Food and Agriculture Organization says it will aid some of the countries affected. The FAO said it would provide one-point-six million dollars to Cambodia, Laos, Pakistan and Vietnam.

The agency also joined the World Health Organization in urging measures to fight bird flu. One of these measures is the use of vaccine medicine to help chickens resist the virus.

Scientists are developing a human vaccine in case the virus takes a form that spreads easily from person to person. Some people have worried that pigs may also become infected and give the virus to humans. However, the Food and Agriculture Organization says it has found no evidence that the H5N1 virus can infect pigs.

This VOA Special English Agriculture Report was written by Mario Ritter. This is Steve Ember.